#app {
  width: 1200px;
  margin: auto;
  display: flex;
  height: 100vh;
  overflow: auto;
  margin-top: 50px;
}

* {
  margin: 0;
}

body {
  margin: 0;
  height: 100vh;
}

.box {
  width: 300px;
  height: 200px;
  background: linear-gradient(0, red, blue 80%, green);
}

.img {
  width: 50vw;
}

.screen2 {
  height: 150vh;
  padding: 50px;
  width: 50%;
  background-color: rgba(1, 125, 1, .3);
  overflow: auto;
}

.screen {
  height: 600px;
  padding: 50px;
  overflow: auto;
}

.inner-screen {
  background-color: rgba(130, 0, 0, .1);
  height: 800px;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}